To find the range of data, you first order the data least to greatest:
7, 12, 15
Then you subtract the smallest number from the largest:
15-7=8
The range is 8.
Answer:
Matt should have factored out the leading coefficient 2 on the second step before completing the square
Step-by-step explanation:
To complete the square, you must first factor the leading coefficient from the first two terms.
y = 2x² − 10x − 4
y = 2 (x² − 5x) − 4
y = 2 (x² − 5x + 25/4 − 25/4) − 4
y = 2 (x² − 5x + 25/4) − 25/2 − 4
y = 2 (x − 5/2)² − 33/4